Diff: main.cpp

Revision:

0:c85d2bc195c4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Feb 22 13:56:54 2017 +0000
@@ -0,0 +1,43 @@
+#include "mbed.h"
+
+DigitalIn button_A(p29);
+DigitalIn button_B(p28);
+DigitalIn button_C(p27);
+DigitalIn button_D(p26);
+
+void init_buttons();
+
+int main()
+{
+    init_buttons();  // turn off internal pull-up/pull-down resistors
+
+    while(1) {
+
+        // check each button in turn and print message
+        if ( button_A.read() == 1) {
+            printf("Button A pressed\n");
+        }
+        if ( button_B.read() == 1) {
+            printf("Button B pressed\n");
+        }
+        if ( button_C.read() == 1) {
+            printf("Button C pressed\n");
+        }
+        if ( button_D.read() == 1) {
+            printf("Button D pressed\n");
+        }
+
+        wait(0.1);  // small delay
+
+    }
+}
+
+void init_buttons()
+{
+    // PCB has external pull-down resistors so turn the internal ones off
+    // (default for DigitalIn)
+    button_A.mode(PullNone);
+    button_B.mode(PullNone);
+    button_C.mode(PullNone);
+    button_D.mode(PullNone);
+}